Pre-synchronisation Protocol by Gonadotropin-releasing Hormones Administration before Ovsynch Protocol Improving Reproductive Performance in Iraqi Cattle

Aims and Objectives: The aims of this study were to compare the conception rates (CR), calving interval (CI) and days open (DO) after timed artificial insemination (TAI) within an ovulation synchronization protocol or using traditional breeding management as a control. Materials and Methods: This study was conducted on private dairy farms distributed in Al-Anbar Province, Iraq, from July 2023 to January 2024. Twenty-five experimental cows, selected between 60 and 80 days postpartum, were divided into two unequal groups. The control group (n = 15) consisted of cows that received no treatment and underwent artificial insemination (AI) when the first postpartum oestrus was identified. The G-OVS group (n = 10) of cows underwent the presynchronization protocol [GnRH-7d-GnRH-7d-PGF2α-1d-PGF2α-1d-GnRH]. The treated cows underwent TAI 16-24 hours following the final GnRH dosage. Transrectal ultrasonography confirmed the pregnancy on days 30-35 after AI. Results: The results of this study show that CR for the control group was comparable (P ≥ 0.05) to that of the G-OVS group (20% vs. 40%, respectively). However, mean days of CI and DO for the G-OVS group (375.75 ± 2.8 and 90.75 ± 2.8, respectively) were significantly (P ≤ 0.01) shorter than those in the control group (430 ± 17.3 and 150 ± 17.3, respectively). Conclusion: presynchronization with the G-OVS protocol lets TAI happen earlier in the postpartum period. This means that oestrus detection isn’t needed as much, and CI and DO are normal.